Store null GL context's state in interface object

gyp/gpu.gypi

 # Copyright 2015 Google Inc.
 #
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 # Include this gypi to include all 'gpu' files
 # The parent gyp/gypi file must define
 #       'skia_src_path'     e.g. skia/trunk/src
 #       'skia_include_path' e.g. skia/trunk/include
 #
 # The skia build defines these in common_variables.gypi
@@ skipping 333 matching lines @@
       '<(skia_src_path)/gpu/gl/GrGLProgram.cpp',
       '<(skia_src_path)/gpu/gl/GrGLProgram.h',
       '<(skia_src_path)/gpu/gl/GrGLProgramDesc.cpp',
       '<(skia_src_path)/gpu/gl/GrGLProgramDesc.h',
       '<(skia_src_path)/gpu/gl/GrGLProgramDataManager.cpp',
       '<(skia_src_path)/gpu/gl/GrGLProgramDataManager.h',
       '<(skia_src_path)/gpu/gl/GrGLRenderTarget.cpp',
       '<(skia_src_path)/gpu/gl/GrGLRenderTarget.h',
       '<(skia_src_path)/gpu/gl/GrGLStencilAttachment.cpp',
       '<(skia_src_path)/gpu/gl/GrGLStencilAttachment.h',
+      '<(skia_src_path)/gpu/gl/GrGLTestInterface.cpp',
+      '<(skia_src_path)/gpu/gl/GrGLTestInterface.h',
       '<(skia_src_path)/gpu/gl/GrGLTexture.cpp',
       '<(skia_src_path)/gpu/gl/GrGLTexture.h',
       '<(skia_src_path)/gpu/gl/GrGLTextureRenderTarget.cpp',
       '<(skia_src_path)/gpu/gl/GrGLTextureRenderTarget.h',
       '<(skia_src_path)/gpu/gl/GrGLTransferBuffer.cpp',
       '<(skia_src_path)/gpu/gl/GrGLTransferBuffer.h',
       '<(skia_src_path)/gpu/gl/GrGLUtil.cpp',
       '<(skia_src_path)/gpu/gl/GrGLUtil.h',
       '<(skia_src_path)/gpu/gl/GrGLUniformHandler.cpp',
       '<(skia_src_path)/gpu/gl/GrGLUniformHandler.h',
@@ skipping 191 matching lines @@
       '<(skia_src_path)/gpu/gl/debug/SkDebugGLContext.cpp',
       '<(skia_src_path)/gpu/gl/debug/SkDebugGLContext.h',
     ],
     'skgpu_null_gl_sources': [
       '<(skia_src_path)/gpu/gl/GrGLCreateNullInterface.cpp',
       '<(skia_src_path)/gpu/gl/SkNullGLContext.cpp',
       '<(skia_include_path)/gpu/gl/SkNullGLContext.h',
     ],
   },
 }